This invention relates generally to computing systems and more particularly to a method and apparatus for locating buried objects such as telephone, coaxial, and fiber optic cables.
In several industries, and especially the communications industry, objects (such as telephone, coaxial, and fiber optic cables) are buried on a regular basis. to These objects are typically buried to keep them out of sight and to prevent damage to them from such sources as lawnmowers, pets, the elements, vandalism, etc. Ironically, the fact that these objects are buried subjects them to some degree of risk of damage. Specifically, whenever an activity requiring digging (such as laying new cables, gardening, repairing plumbing, etc.) is performed, there is a chance that the buried cables will be damaged. This is so because the digger cannot see and hence cannot avoid the cables. As a result, buried cables are damaged on a fairly regular basis, sometimes by the people who originally buried them.
Whenever a communications cable is damaged, it is a fairly serious matter.
For one thing, it may cause a service outage to a large number of homes and businesses, thereby inconveniencing a significant number of people. For another, it usually requires that an emergency response team be dispatched to repair the damage. Such teams are typically highly skilled and hence are usually quite expensive. As a result, repair of a damaged cable is a very resource intensive proposition, both in terms of money and in terms of time spent placating customers.
Because of the high cost of repairing damaged cables, there is great incentive to prevent the damage from occurring in the first place. One of the ways, and perhaps the most effective way, to prevent damage to buried cables is to locate them prior to digging. If the digger knows where the cables are, then he can either dig in another location or dig around the cables to prevent damage. With location of the cables being the premise, the issue then becomes the manner in which the cables are to be located.
Several rudimentary methods are currently used to locate cables prior to digging. The first involves the use of above-ground markers, such as small stakes and flags, to demarcate the presence of cables. With the locations of the cables clearly marked in this manner, it is a simple matter to dig around them, thereby preventing damage. This methodology has at least one major drawback, however, which is that it is easily derailed. If the markers are ever removed, for example by a strong storm or by a trespasser, the locations of the cables are lost. If the locations of the cables are lost, then there will be no way to locate the cables prior to any further digging. As a result, further digging will have to be performed at the risk of damaging the cables.
Another methodology that is used to locate buried cables involves the use of crude maps. According to this methodology, at the time that the cables are buried, a map is created detailing the locations at which the cables are buried. Once created, such a map may be used at a later time to determine the locations of the cables. While this methodology can be effective, it has a significant practical drawback. That drawback is that the locations of the cables are typically not stated in absolute terms. Rather, they are often stated in terms relative to certain landmarks. For example, the location of a cable may be stated as being within a certain distance of a fence or a tree. If such a landmark is ever removed, then the map becomes useless. If the map is ever rendered useless, then any further digging will again have to be performed at the risk of damage to the buried cables. As this discussion shows, the current methodologies for locating buried cables are far from satisfactory. As a result, a need exists for an improved methodology for locating buried cables and buried objects in general.
The present invention takes advantage of positioning technology to provide a more effective methodology for locating buried objects. According to the present invention, whenever digging is to be performed, a positioning device is first taken to the location where the digging is to take place. The positioning device receives positioning signals from one or more positioning stations, and based upon the positioning signals, determines the current location of the positioning device and hence the location of the dig site. This location is an absolute location which is not dependent upon any removable landmarks.
Once the current location is determined, a registry database containing the locations of previously buried objects is accessed. The registry database is queried for all locations within a selected distance of the current location having buried objects associated therewith. If this query returns no records, then it means that there are no buried objects within close proximity to the dig site, which in turn means that it is safe to dig at the current location. On the other hand, if the query returns one or more locations, then it means that there are buried objects near the dig site and that further digging at the current location should either be avoided or performed with great caution. To aid in the digging process, a map of the area around the current position may be provided showing the locations of the previously buried objects. This map will help the digger avoid the previously buried objects if he decides to proceed.
Regardless of whether there are buried objects within close proximity to the current location, if the digger decides to bury a new object at the current location, the current location is passed to the registry database and stored therein. This serves to update the database to include the new object so that future queries of the registry database will reveal the presence of the newly buried object. The registry database is thus populated and grown. By locating buried objects prior to digging in the manner described, the present invention prevents damage to buried objects such as telephone, coaxial, and fiber optic cables.